Damaged and ruptured cruciate ligaments of the knee (anterior and posterior) can be corrected with surgical treatment. If left untreated, chronic pain, instability, laxity and degenerative joint changes are the result. The anterior cruciate ligament (“ACL”) and the posterior cruciate ligament (“PCL”) are frequently subject to traumatic injury, frequently related to sports activities. Because of the mode of inflicted trauma these injuries occur most frequently in younger people.
Ligament reconstruction, but not repair, results in the alleviation of pain, reduction in the knee effusion, improved stability and return to normal physical activity. The method of surgical intervention typically employed has been the replacement of the torn ligament with patella tendon of the patient attached to pieces of bone from the tibia and the patella. These are placed in tunnels drilled in the tibia and the femur. The procedure is an effective one, but it is associated with a relatively high morbidity rate and increased operation duration to harvest and prepare autograft. In addition, in case of failure, new autografts are no longer available. For these reasons, allografts and xenografts have been used in lieu of autografts. Xenografts have not met with much success, but allografts provide a number of anatomic structures, which can be employed as ACL and PCL substitutes. Since partial and complete tears of the ACL are very common, the demand for ACL substitute allografts is great. It is estimated that in the US over 100,000 ACL and PCL reconstructions are performed annually.
An allograft which anatomically matches the successfully used autografts is the bone-patellar tendon-bone construct. However, not only is the availability of these allografts limited, but there is also a problem with length. These include Achilles tendons, tibialis anterior and tibialis posterior tendons, tendons of hamstring muscles and others.